SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e6ebaa07c88fd6904b1228d537def4b30ff89885aa62523fcb64b4bd3783dba' 
  AND token = 'V31+Ti1ORuwcOvMpXnVHhpS1ggG24Y0u/pjz7PyN4Kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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