SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67d3e9e56488478f40eca66df237e5c762a352749e8c52089044a3721a73bc6b' 
  AND token = 'v13VkJh19h3wbisQbkNqXrTmWcofFLWB2hs6wUVsUHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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