SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af881a4309de94c3a33b699daec1b5869837deac4fd9175f8abc559e419a08d4' 
  AND token = 'xcUryBWuiD/MbywxH4Yl0Sp1IXo7FqOtX0L3N/5ngao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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