SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '677ab3bccf3a68697393631b7740aa466ddb0ace5a161811c144fbfdb7d203f3' 
  AND token = 'I2xFTpCdHM/7gXO2xmDAUENzQYX1VYu+ZUBD0Q17ZTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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