SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7b38c96ad15cbdfca979b7c27c4af3401e4b4f7316b6d290c6bae963afb0a36' 
  AND token = 'Lu7tISaPGrspkWhZGtOTMHfV00ZTOCFYcrSiidhi4QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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