SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '485fbb8cabc353235f49877426e0413f84ee95a37805d18f0092be80244bf2e7' 
  AND token = 'CQVi7b0AL/R2/+eKNpWDuCzPfRjv6a1hpzpmrAdKsOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}