SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6eb98b03a0a4a25e330d1e56d12e0d352219db1f533cfe26e9f44fbe7f24e356' 
  AND token = 'FTY5c7/ABZFj1RF9j+75/KPBbeUNsN+xqKEm4vZb5dY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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