SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec5f0a04bf4e52a539d5a7ea578de6cd23063af0cef79560e273951810ce6260' 
  AND token = 'NbGGQRizzGG2AyrrCgJn6fItVdkGUrjarUqzhDz5Ksg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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