SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed2cdbe745a6eafa1ed592e6b57f42c5c22712b4f2aab1280ad71641e73b3ca7' 
  AND token = 'O3Awdbelg+yz7DGdvJfgrbijT9VaEHNjGEDGck3w0qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}