SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d2795977883caf6aa63f6045609996a42236d72163c0cd856dbc61ebc92a00c' 
  AND token = 'ky0jtnxHT4j3oTQ7J5MNk8+nYPdXO47/woV9aKG4Ib0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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