SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c959f129e43cb3239de733744fba16ab912c2081d426293eb50abeb6ed5d644' 
  AND token = 'TqdfNx2e7W7v5UnZKQT5Heqh0UKVWAwiyEkhc4Smsi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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