SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4f05a4ca395b5b31b5a512a43bfd6986c8c10c72d2f6a73801db41158898e47' 
  AND token = 'l+ydOJI7+H3kqAaAVCAJxngo3TDi7UKxkHYxzZfIg9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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