SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '023eeb84039a5b36fba3287a17a3472a23435bc77b60ff513951cd1306790bc6' 
  AND token = 'jn1V8u4V+QSgZFWl91pJG6wrunLZ2ggwZuKl4AwX56I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}