SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1ef6a7890feb8f10f87b8e6f9e21121d34579185ce4354c9c3bc996151605bbd' 
  AND token = 'k/qIY9/e1pMWlURaZWbGyq5KFMpES2tH7RC/ihFAycw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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