SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f8408f8604e1eb3ff454cb66bffa54e2c0ee30ee9821191dfa2df4051841857' 
  AND token = 'G9OzbFswh15F5zSj+IeZBxmj+gGhI3Z/WpwS4sjyovk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}