SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98629bc5d39d8ef6a42fd712a315d846de9ea8c17c9410016cbbcfdbce6c5bf6' 
  AND token = 'xhP++WHLgzIuqKp2Ev/lku83xw7Iv77Ad2R+lrl5NLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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