SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c6260b411dfab8ca524acd9b473bc28813296ff630b4ad5b5ab5f7163c75f0a' 
  AND token = 'xdEQnY+YgfxtNP9CE+AwP2DgfynyFWZG6/tRl1WPESE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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