SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '10ec30dc0c4a2068a57bc3535faab853622a43c6a0245079b78364966c0a5f81' 
  AND token = 'WIlcWRxb3Km29SXjhqW15a6L+GYzghLbHDy/Jd/9iPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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