SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ea61f9f3d72bfdd47251a896c88e4eb928eac5ac11a4acf127edcd19901830f' 
  AND token = 'lW8eESRCYI5r9b18XT4dcFf4dUgOWljPpJ57R7jPbaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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