SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94f68bd6668548327e52306c92fed30cbeb98abcfac921710b5d0e8309797f64' 
  AND token = '0FexhMqaLqwHMrayfwcq5ICfKBq6U/uz6jLpwLgEC8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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