SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6885ea93aee397a681cc8167b42a6dec134f32a782aa00c152b03043114bda63' 
  AND token = 'TMAhwRDsDUsS7vPyHRnaQ275DXCIFjLTlhbGs8kREuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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