SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45fb20ec5d6559bf47c46f0df8360b1779f3ef4a353865d3ee7590626b83ec54' 
  AND token = 'kjEBCoJmSXo9mUFfFzV+qza3VmpahRZOm6OLQDEKcLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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