SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdf7e8815f48c8291958c25a9f8e2353add225d83b38f43a6fd64362ab6f97fc' 
  AND token = 'ww9nByh5TODEyu7lZtN4AyTPXQSTJCGCy07XhuTfVeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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