SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e47822d67e9abc6d142294391bac569d1679510b229d9b442308cafa99a25c' 
  AND token = 'pZQZ2G3YtZcEaSXv/Q5qSZCUMR31/GEmOJDMuc65SbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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