SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63cfab244df087cdfc691e46518d445410f03419535301cec672cbe83ee46b1' 
  AND token = 'JWw6CPHrGZelh0KPKHCkay3sR3j9cZvN3ZUN9S6Ktjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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