SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c87f45d5f2631535cb540510afd8f21c0baa83dd5f3df5656a8fcc78910720bd' 
  AND token = 'xcVGh7ihLn7FXrSF5g/kXRdljxNXKnkJ/En1aUtBd/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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