SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bbc478eb199858fcd271b3a2d9b670b4186be47216b232bf48cf7df8cfdb38d' 
  AND token = 'W/to/w+MLSZDg9YLuE2Ul1AhneMkUNx7UJcNBmuq0zw=' 
  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"
    }
  }
}