SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33e7eee55b7cd785d3f985f43647443e4d09d38159b477cedaabaaad12b22b98' 
  AND token = '4ckoRM9kae/nRqoKuIplxHcmJ2+2fVhoKVebMfdnsKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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