SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ab4614fd844647237c703b17525c26503c3f02249b2265923ad99b73f7575a98' 
  AND token = 'Z2+DxZ9BvIQIphovufUoK4Z0aO+EcAHvdo0nlRRW1mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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