SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8313655145746c6ddd0616d98ca7e96d3458d3d2298c069ddd29ea033776b4f5' 
  AND token = 'lKBojurQn2N5YgbpVUwagTvLQpkxZBr8HneePjQLJTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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