SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '161a5764be7f4dc3f884a9208873cae0461d92e74294d43f62999f5bceb15053' 
  AND token = '6+gRHFVXHlBZMirJiecUGxDJ0QQLtOuH1ckduK3+cc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00154

JSON explain

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