SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43691a25fa92700bf2e9265318b399b077b9883fa1619faab7a33fa946da23fe' 
  AND token = 'PT1x6v3SdXGuPE3qUzWqboUiI30XbRLaoq93MXGxjHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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