SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4e929a1df8af02869a42f837a4c41330f622651c2e0f16de9581f9111275183' 
  AND token = '9kd2KLQ/X4gd9izKbdvsxy8GY1W3kVMfE5jqTiQu8gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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