SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca1455959a9a54053e9a7b5999235d865470d9de6f8c32ffac422072c3298893' 
  AND token = 'IwJ6g2noeCJqAkszYiLM6NkBLiKdRsZ1teeFLhw0KD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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