SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be2a9e272bc1e7f2f93748a7ae40e9cc31d39b5a2d5b9da4674eda16de2b0870' 
  AND token = 'oYBYdYV6aTABhU5/bY5Pne1deNa2O2emx+lEBHMrsKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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