SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '755f3d1870a03ab4ce8a8b90a8e64ceb7b612c5110f184f738c8512fb97134c2' 
  AND token = 'mBppBCo6GWqTugW1IJuxYsMN7zGliKCvGeY7/c3anos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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