SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '221585ee17751fabb2e1637c321302f0befd19627553a1bc3291163187a00215' 
  AND token = 'qUkSelLJFGmKrTZBp5Z/FTBncIUfG7Ae3aFjIu8DvJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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