SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eae183dd1d93d992b2f506295cb65b09e6e3867efddafcc996ecc4633142d43' 
  AND token = '85oKWQZDwJAh3vmWGgriXnQYZBag+02N2yKQxFJGEsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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