SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6df953a46077ae39de1dd9bf5f86901d3889bd9a1faeac93194d1110da365d3' 
  AND token = 'F35I6CjCJufRfaiTLuCOO9XMzcKsYGRcS1kLZmlxDsc=' 
  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"
    }
  }
}