SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd7860b46fcb2b35dcf26ce437889aa29d460ff6596c7417e9083a39aee97290' 
  AND token = 'MHB5RD76GS48Gq3OOEunHNZBGnMwjF+jm5MYdGumKxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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