SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '758fe1a1c99cc8d1e72901609869c8b2bf65dc193fcfb3a890f1fff849f74d79' 
  AND token = 'CWrJQw6V1LR6JpgxLwMxf9kpkbcjtq9BqJCGWtRW4Bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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