SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd12e690ce256a5f1c3542b9d2b75013d866708873cb92cc354ae04e4fcc998a8' 
  AND token = 'OCg9hvL5pOolJA3ZwYw1er2dpzl9SWBisoqzx2JBK1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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