SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ef412acd9a989c30e2ee0928e6a4ed1cf14992311ab9b79d915ce662aa37000' 
  AND token = 'SK+JSCYw5IGh57l8a0wM3jqC3l4zVFrgfUunggRZMsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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