SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6702c444c67c76330a3c69f16252c57533d5bec27cba709655f0efbb9dc22854' 
  AND token = 'HYirM7WLZgKqHfzxFiue7OWCYLEcygv618qTjBQAJOM=' 
  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"
    }
  }
}