SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8322fc103f542f63d10d110594853ed453b3fd60b366cd356c0572d71d4908f' 
  AND token = 'Ft71BbO54GPNZDvjqNHjvnzQsJEv7Fpiwcn/xoNrhEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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