SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e5fe448704a4685e48f74f54d582629502a52f8c7790587206fe22835a1772d' 
  AND token = 'XCefKxVxeVtwZOrbJlpqqslve3kPyWTFgJKg/3QBZc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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