SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88505eaf23878d5a299296dfa3a5d6eba87bcc07ba22fbc1b3cefdff70565dc8' 
  AND token = '0wBrKGWCPT5CztCth+IENlBgfzmQ5bXh52aWenxf23o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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