SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4ade7982dca5d5254e22edef1904d24c451277f4160248cde2713634f6b020f' 
  AND token = 's41zHwVPx9GKpRTARGoxWBRsuMvCe84SOs6pQqXHUOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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