SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0296eabf5e7eccd850f819a9d08b1608d64683e5df03e0aef0d86d611ca4f05e' 
  AND token = '3Sn6UL92JOPCZkbIxWcXNoOAGqUC1zRbl9wSO7dwvho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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