SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9ca61f76773a8cfb75372dde3f2987805f6fd8274d493438a08edd4738abcba2' 
  AND token = 'LZFvYL9r44m4pbivDg/ZAYZBLKUugQGIhkl5pks9Mqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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