SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2df36600a8cbfe01e75bc231193807883156d543149df32022127b122e03d96b' 
  AND token = 'Ds3peoiidcqyq5zhXaRYMCWx4Ruv/3RwtveLyn5OO58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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