SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fba7a12d8cf8b84a4b95cea27d75200a279fb948e9e8932ab4f27cd27ce16f22' 
  AND token = 'DqxzKxw70QB62B2gYi+BEWKuCQMzlemnvqPvKdVLdfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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