SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6568458e7fffe9c4ddcc7a48e4e19b1036acd78893e2a10aad2b9a61fa861e89' 
  AND token = 'a9mj3mCe8i6yHRWvGiwKcNPiK/HFMAJ/tHKU2PeMmyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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