SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35319de457fb297b3e90666725d7aa2d33bbe13b25d3a7f1804ad4a2da616d6e' 
  AND token = 'TYVPsDVg9vxDSBP/A9+XM5QYziVTrPe6e2/JwRXhtJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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