SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd790e2786100dc6455f20a9bbe6cf69245af0327b48f0867582e549930b9e706' 
  AND token = 'X65Lkw+c3SJ57An9VnKedsEgIoTR/ZXQRyzfuz4LNj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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