SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b67df7ef2aa0d9e39c424790d6faf171da61cde15ed1ce587f0064f51f3086a0' 
  AND token = 'jowXsWP0z+v2jlBzkx16KV+yzPLJ1RxXkvTm5TUb3KY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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