SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aa4fcb5a8ae26f50d7c6e1793523cf7a6c553e130abcc238539b758a27478b2' 
  AND token = 'qjaHALngFU41y47jFe5jk7QRn2F/Ux9Qs6JuKZ3CGBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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