SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccdb2af5dd32607713d7fa512391deb4ee5f6101637cf2ae8b15c5cf3ba4e99d' 
  AND token = 'erbP5ojcJCjpaSX1deTye2hCEbO8/ORk9xm+zE8n3PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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