SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d7d30d81e74a82f0bf3d5e3a908cd0583ef60d175c0ac7266c6bb454d5c905' 
  AND token = 'XMmalPBKZJHjBwKuPJniTifd2E196r8C/G2i8xNElrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}