SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbce4ddb0cc5c6864ac57a990569ddd549b0a3d96eb5d302c2f82bf70c6aae34' 
  AND token = 'RYv9dfGKVVdoUjUCWhZfAGUuu3ERJhTFFha+szI5Cms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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