SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f4beaf7db6e0cac5e52e15d3419b84859180aa9ec34cfed561c11db96e18540' 
  AND token = 'KiKVDTcUfpaCzv4lYLVNeD3C8EVS/X3bQcvRBNkNDdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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