SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2387d0a52e5448ca7b51bc4c93172111539b06669064152a69a0a5ac32fb5a9' 
  AND token = 'wW9AuUUcs8IyiFl0zhkDspR7Ps9DLAnWNNeN5zU4gtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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