SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca5f8baf50586299020dd8d819cff63b7e8433986f1d3b26af89b26d663d6a2' 
  AND token = 'l4TNqiISDfHYFtsJTACopOz9Rsj+VHaZwgAqGXbpBso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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