SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54ee529dc541cdae204762b4d77847f37980b40067ca268882f4e3ed736d8f61' 
  AND token = 'W04eJkmSdUpeDCo5El/gczNbD3UQpMPbSTZ5oo+no2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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