SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3fb71d84a49340b5b4c6054618c6d2587dc57f54f4a8da19170c793616e7f4b' 
  AND token = 'pabkZEOZkh9B+Y84LTqfLDxjzJOcoceUd4F9KIswEjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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