SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ecfd22844327b89d8196ba938ce4d53c20039db8117912688823317f506857b' 
  AND token = 'zvePYodgPDjdYvB3uH3ThexqDLwjiVrh151HD/FTCmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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