SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41e67b82ef9eee6119f4a5e91f305a4176131b5387a13349edd81c0168dee706' 
  AND token = 'llBhjnIeYop37j8BHNhajFhpnqIkeG+A/U4oEw4rXhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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