SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e740070dfa8edbd3de4ff1d2c096f372251a58fef728516d4c3264b1b28a212' 
  AND token = 'GgvrITuauk0aYrmwwerYVvMLQIpPuKrtWEp/J2WZaik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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