SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0540074c3a7334006e318700c6ed4a6b59289391bc25f9727a2323d032a232b0' 
  AND token = 'EjdHR8+rqsWwmaxJwFHI3RBuz74uEZcIzjXwBo5QJmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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