SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42707a324a0ebd00efa78e6d24cd18e219f4901681ba2399ae08e6ed30863a6a' 
  AND token = 'ysq8ltQQWv4wA0spZ0r6SXL7XqH2o6dH5zDzfVqwipk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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