SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42aefcc3e33ab5f7114153da1a1387693c5d4f4bcd3c77fb3e74183d9354ebc6' 
  AND token = 'ixseptub6juWAv+f6H+WhoGq9M2WfaqflDVt67Hs9cQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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