SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2f9139f162dd82ac1225bb73cea4118831d76871366126b8f070496cf8f4793' 
  AND token = 'QQOORafk0Jf6G8ay/fw/wATlKQQtZDsLihIu/KhbUvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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