SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2d23af53c8736278213d55e3502fe64fe5628da4901b735498103ba75570e1a6' 
  AND token = '5GYzQrEZDpV9IIG8Dkj4SBEFTErUwFUKT0u8JB+0W/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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