SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72e9b6c1a332a7096a02bac94d98be782313401737db2efaea9af674efe9c44b' 
  AND token = 'Di63TAxg4qWfd8Sm5ItXapgXeIH2VZg4MIjjvLiobQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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