SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f0ef098fdb394a6f62e8e82274a1bfb7b0dbdf4410872402f9d47ad7d135287' 
  AND token = 'WKfPMJfjpFlzXSS1/Qvn2gPPOd2PDTM+UHEEnX8GILI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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