SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93e0fc05df11617a92a84f29c5685a7ed741237a1612e80a5b941fed5775a49d' 
  AND token = '9ZkgMjLwbAsq/tIvrxMIJJjQb+QdYdfVE3+cSZVnruM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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