SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96060ac5c381a88e6bcebedbc26059db5eab1a1e99bf1ad90a45982a798bba2b' 
  AND token = 'ygQcZSTMkQW5A17kc5pvzqlWIuSKmvMUYS5rGIV2QQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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