SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f453340c6d4e4f32eb24ceefa023cce96c1dec57eb3a8b16ec9fb2286277425a' 
  AND token = 'z+mk7wiSe4FoQqVJQQdukko0nfVVJYbIkGfp7UOsJCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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