SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae40c6c0dcf5d494233fcb970a578d921acf986e1623e214b5792e7c4a8af5d5' 
  AND token = 'IMbxtB80kpfhLG1RHQuREQceD0vnMTW+qJhDg+/k5+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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