SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca992b9d698afbe760c96225208da4bccd80bf47e80107b4be05ccda31a83b2d' 
  AND token = 'YRkeeSt43b91qo7IszIQBaqXfqsRWwro4DdXW1H8tYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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