SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d70b9fcade60851875b47850f4cb7d6ebcad7dc0e1a2c54a22dff7bb7017874' 
  AND token = 'PjAu/mZCQjCp3KN9WDtdMzPiMhXciC+D1aS49cqdoI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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