SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c23206b06372a137e5ec72fa7cce4aa7fd46a5271cd7b0d3654895a85d374f8' 
  AND token = 'Eyh99KIv2R21oPCHtzeXtKoYEs/MLHQVbHEmeCuwgjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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