SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e3decd350916b8012fd0b75cb225533de004bbfd9473183c686531da70222e56' 
  AND token = '9fMox6etLv6VIv5P57eemzU2QDO/47U21bwwlm77aPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}