SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53f6fb34f201ccdf6b58c6210be2a29a8cb7fe7a8e6bb28ed658a54701d3246a' 
  AND token = 'ruXVqNRS6RZIHAUZUoGzTjzszlMbruasv9ueUHItoFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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