SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ad81e38b3b4d07e91e8776aa4f82b6d4476dca43451bdbe329a4a826f067bbb' 
  AND token = 'FqGqOMzQnuUHsNuhBAkvZHB6C+GMSJ3ctjxvevtFd7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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