SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de7b19f9aba6ac3dcaf869c641679bf98f4366281168e44e0b52305b765b01dd' 
  AND token = 'wiG3UB5fLkMh/cfhuHfIHW5dbjaUrY7QvgzzU1pvYdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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