SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40a3f6020f0fee696f30a2ddeb57b1db3451b4fbdfc9cd4c1289594afbd469b4' 
  AND token = 'L9IH5up6JCEn/lwMIOGQvbkzkPu0Uk/foYo1oFeE2Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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