SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc6361f4413b0a8301595ddfc2e0528207c519fdced5373919c3a4c9ddf5a624' 
  AND token = 'CFCwDMXjUv3pn4rJ3csNdGZRV9sUQUAgJhYfL+wGuHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}