SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73fb0e00bd0cd61cf25c62d45199e8e981c6acbf1abb7601ffa844215dcd9fb7' 
  AND token = '/0HYAD3u/Pn7cOyvB/hhzHHjZx5oo+1R8MdqGgxMIX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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