SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2875a0d0959c762288f0e4332abe931c5a6ce8572c17f6375aad4be1f67f1d5f' 
  AND token = '1FJRj3iUDwbromnuhueAX6sL1wNYeCpkOnhqCl5myIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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