SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b9233f918ac623e1827bcb73cc44ce2fd6724f17a6470e318a76f9d7b3374d6' 
  AND token = 'PkVhESVnmJBF6WbV/anJwfqhdY4kZ1jE+puRyPC9+0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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