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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c05ecf6bca5dc4360a0a368e658a87747aac6e336b8b12704fbfb6e5bb84b5ac' 
  AND token = 'HZboNFq6IhzRRoAFL1MCGSHRk5TSu+bdVMb8DqY3aQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}