SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '029b6602188a769805390e0e332558927a49f1d80a1124bb35a7f9a6fdabacab' 
  AND token = '5jyOZJ7ZxAXO1hFQDoHjap40/gsvz1fqo4MeJk2qckE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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