SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '156afc56434ffc7275a7efccbcbe236c0f562aaa3f10a78570f71efcc8f91b38' 
  AND token = 'JOEvzY0qFBQYMTqlX9WbJXvE9+D28OsgKtfw+Yh4X9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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