SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14689ea3a46cb21cc64a664ec0f706520c015b7c7a4436b58dd08d10990c4185' 
  AND token = 'LGpihNeZpO/jlHnFIeLLoxXbTibf5JbmJPzo2aeNS34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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