SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6bca3fefc948058f9f9d5d85d785005cfe8cffc31c37b7fe0e2d5f36ce621cf' 
  AND token = '8v9HruGUmQg1D361+50gKe05+FZahVTUOvARCarWNIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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