SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '270cfc5722f84da8599b555f9edb636eb524f87944908e02dd40d8bcaba9d88f' 
  AND token = 'iig2Kc89T6YYEwDZ+TCuZ8nho4nNaarsm6IoN0eg1X8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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