SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e70691d2c96d534f8697b0dc36b309025b22e83dcc71699494a1d5fa383f77c7' 
  AND token = 'Xa6cBUj6HMlMmhGJ9k9zT8OdtWajm0E7woVqhbKpw+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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