SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f5a171a4a77cca321f3ebf0b28df5a8819eca115b65f4a7bfa537011141c6aa' 
  AND token = 'RsHgK5ZFpGhv6A0aEulo/VPwkOiTNYTWEz40rJTopMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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