SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8171cc4c390fbf88419cf77c24c90e17afa0e18e532d6682dee5152c48aca7f' 
  AND token = 'tsKXxrWhQLH/GZXhPVEmeEpNy1tIWPwrMcFi/qR6RF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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