SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca3fb3c44dda3c6cfbdfd9675cea22221bec6d39d1cc233f615563a365d7bc24' 
  AND token = 'REqNRKs9gmPpDN8qgCDOPa7FKDR7HNYMqwdTb+y8rpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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