SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89486c9b93ed1bccd6b79a0039d36810ba97687e0b733fa26969e7eff4d5917f' 
  AND token = 'KVWqFrBRGLwDdlUwVxH6CfznvysABpbIOsivzXb286M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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