SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '276370510e7681b5623759eab335e937407b7a2b7cdabeab0ddb9785ea4cbe25' 
  AND token = 'h5QXfbRUcAepvkBfp8Rxp2YTkpmlL9OdpmdjYoTu8EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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