SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c44abb39d036c582988b627f3318e5ef00caf33490ffa0a7687d3f58110c53e' 
  AND token = 'boBEetdZOc3xk5dlOzKfLtyh3N+6OXJKYeczY6ClMdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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