SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3888c9aed535c054d80692589d7aa27d24fa3ab45ffd1d1bff490a803cf0be9' 
  AND token = 'W9oGddg3+GvVJAtuZm25pyoGjDJ6Vk7F320dqcEjapc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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