SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '701c223912dcc127f2b05481cd0464613ad817290b241159b39469d995476813' 
  AND token = 'JBHSE961acvVwPVQe6zLj9p8XNbD0wHT24VYl3a1yxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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