SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e06a1d86508605d910b8741bf53dd45de3beae45848122a9c5d7b46c07b675c' 
  AND token = 'mOD3GZdVCw5fEzrYnjnB5zBqvEBsl0SwSFhv1wTVzSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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