SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '471e62c7695795842d4623720fa948b8361f832177df925059822c325b6a6944' 
  AND token = 'wZo8mBgc5svon03Cs8sGH3WYBju5cIspRb3y+0hJkZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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