SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa35521b5b2954d66523e202e346cba6a8e10c60ef08bd4e3b11770e3e281a30' 
  AND token = '3IfCJBjq1lixdRMY7+bK+KXP5mUp9yT3fYLha7wNLGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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