SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fe32f46f5d51c586de691a9cfde9b74c5ad6a5d916e2f9b36f3992d2bb6c24f' 
  AND token = 'KISU+mX8Q87XxZIGRmTfqMTY/bHLDokZmwAYNVNYoEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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