SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3c371f3c881690392e9e53d1843a4aecd02c9db97157a2e8af6c6ef75f7b150' 
  AND token = '2xyfIwMQoxablSuC1HQVGxKOILBoBfcYDIHd/fT+T8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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