SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f95e5d60f028197bdfd3af9ec3ba52f05180a31b7626abe3c6ecbe95da3dbd8d' 
  AND token = 'Tss3R4MRqQoqYgrwqc80Xv+YhAe2qhlQGwy+Dl3PujA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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