SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52fde72dfd1080732809483e538e8c8893dd934a1a911ec2c5195014ec387ae5' 
  AND token = 'Y1lKVQ8FagpNNdTSnRQlCShvu7UibKRvSjT+NRvNMNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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