SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f787063daddcc2da56d56f26305e0147a47ecd2d0d9509c4bb201c9cfda50e0' 
  AND token = 'yjeLgs1bHThRvCZ8b+sEIyuh9XhrfrlAzYEBjiEgUxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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