SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e4bf8e4fd7533f0a42ed2c74a28d002553d7b5e97aafafbfe69822bbe102ae1' 
  AND token = 'sGBkMWZ2XlEjQANifQHAm1d/js0oeT+lzqVeGhLrfwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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