SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '98f8e3c6618421aeab8a9c73c29d55d94e4a4f396a536d3f99b473453da5da4e' 
  AND token = 'rTceXp4lKijYSn4R9XWTbyvCMKt2l4pKOlieOGYsm9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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