SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47de12f4472ba5904d277a7cd3db1ed3ea8008f3ddf19e9906daaeb116436fc7' 
  AND token = 'doqOjeRK0xkpvGgON4BVZZRGcHShTuqbFyDeBY2yyFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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