SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efdbe5bfcc29ae7050e600196da61d888e69e4bb761b3fd6957c0173353a357f' 
  AND token = 'uIVUsIcM5ph52V+CbT/KFQs0P0c0nG5DvjTmO0NVWTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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