SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d491e3b079c487edc5e0141711acacbecbd0f64f3e76dcc254f18ae8c287eff' 
  AND token = 'kKIfSYJMPATub4vnD1oTQVaI/GQN1TowXZRZpwYUteM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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