Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4b7cbc87ef6fb402cfed2c29854ee6872457880da4403fdf584f9366f83c7c2' 
  AND token = 'QrEBWWwq/5B6ymTa2l4bWSZ0N1tqpVXIfR7jptz0AQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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