SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df69c506e42089ba97854c14f337ff909c0d63ecffa86d99833d78239bbd28e1' 
  AND token = 'GfchdkfHvt9JimNE7Z4zkXyKnbB8tbzyTS2H9A2csJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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