SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '70f465e0a15bcba809c9c1c9390c694922fc8dd7397a328a136625ba4c3c4355' 
  AND token = 'mIPWsDJ8zLv8XSgXRGGCMRj+VMLDtftNWoz0HFcDVzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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