SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3bb03975c25026c6d183657552ca516fe80d8dd3179ee0e8ba768af1417ffc3' 
  AND token = 'K3R/C/TAGdfwIEBWoudIik5U+7NTOI87LNI89b5+hrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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