SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12a12679dc53570453bd31052fb7cd4910b5d9c5f62ec0cb7e40eb4a63f95b48' 
  AND token = 'h7S9TYzymXlIGUs8OuT8o8dqVVuMCp6q1GpHGVMNWPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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