SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42409633a6144a678a88c195f66f53b764c99a8926698a31261bc41643ef9808' 
  AND token = 'Ew6XoBRGQ/jLGvheEelTaIpyQsuCyG5uitVbNL+M6k0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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