SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f0419d334760be06047c7e229f549688aadfa9ca059c69634d128aeee6ed25' 
  AND token = 'EnFBBLrBTHXYtij/NTOKlZlW7KCkwFv/9xYgZcYX8GE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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