SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8ee012548aa1c20b915aa0d0cbe3890ff6c572c00c629ab5d992a920d98e465' 
  AND token = '6wj8c8roQOb0UqmQzihyoAxrIBwLyDtu/rBLrFIzXec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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