SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ebb73c81e3e297ffc1edaeb9c0f9b02133b6cda63641c79dc2e098f0a4f6051' 
  AND token = 'T6t024oHBrsVfnNRGN5I4Vyd5F3ClGBHL6UMB6uDqo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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