SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c25923b56ac9865129b70c04d097e6beb8e95388169c64eb2697d137f2fc783' 
  AND token = 'x3e6Rqhz5eDQ9Bq3Y9Jzzjaj/YdPpVhMZOyDzXhOWWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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