SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b662533b3157b7076a543b55b71e5bdfdf00a71c0900cbfa3776ca4eee1fe8be' 
  AND token = '3I2uNOSXYDxymsmCJatyj2XVsuNntX6pnkPiaOdxA5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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