SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77cefaf6e11375636cc433824f5342c41c8482500e0d3a73a8505a5f3ced0d14' 
  AND token = 'xnKl/XEwDwo8Xv6noOlBKKQwJfnMYYSOCD+/OYYLu5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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