SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec518db78620969073ac5279689147ca128434d30dacb427083c1b999f95c0fb' 
  AND token = '9OowvdojqQ38NO+htCF/QTZ6rP8maoVvA7OtgZtR25g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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