SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31d2b262d36e39399cdd828943e32349f6d67f67cf3e9cbce9c1e09e8f525f7c' 
  AND token = 'oFqrZoKpiOfyLPDYdf1PKxc5unhfNxtPlMreTo+Y2i4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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