SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '928bfa920d0e1a57d6f318060fad6fa14aad9e3b2280aac86ff9386ca8193cf7' 
  AND token = 'fAd522ZkDhGZeGUCDzg8eHelahR4YDPzBUV/FJbUOMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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