SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24edc42d4f678cf2fe8670da76552b0646f134a03d9c19562e8322f05b96f77d' 
  AND token = '0kv6gAZkwUz6/fht8d0V79RbYLGAyCdjXeJYwSqZCkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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