SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c083a0dbaf07b079ee7e07e05505636e764f1116aa5dcb9f53c8e2343c46db9d' 
  AND token = 'Hiw1Sj1tVuJKO5o50dYHxK0uFiBj7wfw4Ck6IpF5oyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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