SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80e71d098a030a578e7523cbf4846e00005365db6e8f522a520b0df410a132b4' 
  AND token = 'ixpmH31jyV9lZxuhLko+B0IqtAaX8DuClLeG7jJMRoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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