SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c59cff8af205047bdbcb144465c0a6cb4a700fabb6248b3cb6fb525aab491cb2' 
  AND token = 'nhv8bYMbMCPV9hwsroTCo7HkirHtIxlUu1lVQZSYCTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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