SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a3859521550354bb8802ae0711b031cbf43be68af92ba01a96c9d6f0a209d4e6' 
  AND token = 'hUYnnkJ+uaJq1l0NnVa6ViBY8O/qqfP38M/8+v42uBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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