Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f65b62c5229f5b919da1690a09dd644dec0fcedec50f34a1706f152c003c6aad' 
  AND token = 'LdlczliDQxkITuEj3YhlwNyw6fAmGdYEbXsd3PnC520=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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